replace writer.Close() with write.close()
replace writer.Close() with write.close()

1. close(this.exitChan) in writer.close()
2. replace Mutex with transactionStat

glycerine/go-nsq,server-nado/go-nsq,mreiferson/go-nsq,deepglint/go-nsq,huangping40/go-nsq_hailocab,bitly/go-nsq,grepory/go-nsq,jmptrader/go-nsq,DanielHeckrath/go-nsq,yepengxj/go-nsq,judwhite/go-nsq,nsqio/go-nsq,huangping40/go-nsq_hailocab,bitly/go-nsq,DanielHeckrath/go-nsq,fayep/go-nsq,deepglint/go-nsq,absolute8511/go-nsq,hailocab/go-nsq,glycerine/go-nsq,judwhite/go-nsq,mreiferson/go-nsq,grepory/go-nsq,hailocab/go-nsq,fayep/go-nsq,nsqio/go-nsq,absolute8511/go-nsq,yepengxj/go-nsq,server-nado/go-nsq,jmptrader/go-nsq